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TitleLate Quaternary depositional processes in Orphan Basin, northeast continental margin of Newfoundland
AuthorTripsanas, E K; Piper, D J W; Campbell, D C; Jenner, K A
SourceExploring energy systems: 2005 Canadian Association of Petroleum Geologists-American Association of Petroleum Geologists Joint Annual Convention: abstracts; 2005, 6 pages
Alt SeriesEarth Sciences Sector, Contribution Series 2005196
PublisherAmerican Association of Petroleum Geologists (Tulsa, OK, USA)
MeetingCanadian Society of Petroleum Geologists - American Association of Petroleum Geologists 2005 Joint Annual Convention; Calgary, AB; CA; June 19-22, 2005
File formatpdf
ProvinceOffshore region
AreaMargin of Newfoudland; Orphan Basin
Lat/Long WENS -51.0000 -46.0000 52.0000 48.0000
Subjectssedimentology; marine geology; basins; glaciation; continental margins; sedimentary rocks; sedimentation; glacial deposits; water levels; sea level fluctuations; till deposits; turbidites
Illustrationsbathymetric profiles; stratigraphic columns; location maps; seismic reflection profiles
ProgramGeoscience for Oceans Management
AbstractOrphan Basin is located on the glaciated southeast continental margin of Canada, northeast of Newfoundland. The west and southwest shelf edge and slope of Orphan Basin are deeply incised by numerous canyons and gullies. The canyons extend to the basin floor as channel systems. Most of the channel systems have formed on top of debris flow deposits and are estimated to be older than 45 ky.
Interpretation of sediment cores indicates three discrete depositional intervals during the last 45 ky. The first interval occurred prior to 30 ky B.P. and consists of moderately bioturbated silty-clay with common IRD. The second interval occurred between 30 ky B.P. and 14 ky B.P., and consists of moderately bioturbated silty-clay with common to abundant IRD interbedded with abundant thin bedded sand-mud turbidites. The fine grain-size of the turbidites implies that their origin was probably from hyperpycnal flows produced by glacier melt-water plumes, suggesting that during this time interval, the glaciers extended to the shelf edge. The third depositional interval occurred during the last 14 ky and consists of moderately bioturbated silty-clay with rare IRD. The dominance of hemipelagic sediments during this period indicates that glaciers had significantly retreated and there was no direct terrigenous supply to the slope of Orphan Basin. However, cores from channels reveal the existence of debris-flows, diamictons, and sorted gravel and sand in this inteval. The widespread and contemporary occurrence of these mass-transport deposits indicate that these events probably originated from large sediment failures produced by earthquakes.